centericq is a text mode menu- and window-driven IM interface that
supports the ICQ2000, Yahoo!, AIM, IRC, MSN, Gadu-Gadu, and Jabber
protocols. It allows you to send, receive, and forward messages, URLs,
SMSes (both through the ICQ server and email gateways supported by
Mirabilis), contacts, and email express messages, and it has many other
useful features. An internal RSS reader and a LiveJournal client are
also provided.

cfv is a utility to both test and create .sfv
(Simple File Verify), .csv, .crc, .md5(sfv style),
md5sum, BSD md5, sha1sum, and .torrent checksum
verification files. It also includes test-only
support for .par and .par2 files. These files are
commonly used to ensure the correct retrieval or
storage of data.

CGI::Application is a Perl framework intended to
make it easier to create sophisticated, reusable
Web-based applications. This module implements a
methodology which can make Web software easier to
design, easier to document, easier to write, and
easier to evolve. CGI::Application builds on
standard, non-proprietary technologies and
techniques, such as the Common Gateway Interface
and Lincoln D. Stein's excellent CGI.pm module.
CGI::Application judiciously avoids employing
technologies and techniques which would bind a
developer to any one set of tools, operating
system, or Web server.

ChemApp is a programming tool from the area of computational thermochemistry. It is a library consisting of a rich set of subroutines, based on the thermodynamic phase equilibrium calculation module of ChemSage. It permits the calculation of complex, multicomponent, multiphase chemical equilibria and their associated energy balances. ChemApp is available as object code for a wide range of platforms and as a shared library/DLL. ChemApp "light" is the free version of ChemApp, and although it is restricted in two ways compared to the regular version, it gives you almost the same functionality.

You are captain of the cargo ship Chromium B.S.U., responsible for delivering supplies to our troops on the front line. Your ship has a small fleet of robotic fighters which you control from the relative safety of the Chromium vessel. Chromium B.S.U. is a fast paced, arcade-style, top-scrolling shooter. It uses OpenGL for graphics, OpenAL/SDL_mixer for sound effects, GLC/FTGL for text rendering, and glpng/SDL_image for texture loading.

Ciao is a complete Prolog system subsuming ISO-Prolog with a novel modular design which allows both restricting and extending the language. Ciao extensions currently include feature terms (records), higher-order, functions, constraints, objects, persistent predicates, a good base for distributed execution (agents), and concurrency. Libraries also support WWW programming, sockets, and external interfaces (C, Java, TCL/Tk, relational databases, etc.). An Emacs-based environment, a stand-alone compiler, and a toplevel shell are also provided.

cingb is an attempt to write a Gameboy emulator for all kinds of platforms. It plays Gameboy and Gameboy Color ROMs, includes a debugger for step-by-step analysis of Gameboy programs and might be also interesting for educational purposes.

CircleMUD is a multi-user dungeon game system (MUD). It is a derivative of DikuMUD Gamma 0.0. A MUD (Multiple User Dimension or Multiple User Dungeon) is a computer program which allows Internet users from around the world to connect to it, create fictional characters for themselves, and then interact with other real users as well as computer-generated entities in a virtual environment.

Circus Linux! is a clone of the Atari 2600 game "Circus Atari." The object is to move a teeter-totter back and forth across the screen to bounce clowns up into the air. When they reach the top, they pop rows of balloons and then fall back down. If you don't catch one, you lose a clown.